RAWALPINDI, Pakistan (CNN) -- A house arrest order for Pakistani opposition leader Benazir Bhutto has been lifted, police sources told CNN Friday, bringing to an end a day-long standoff between the former Pakistani prime minister and security forces.

Hundreds of police who had lined up outside her home Friday left after the order was withdrawn. A smaller number of police who had previously been outside her home providing security remained.

The lifting of the order came as Pakistan suffered its first deadly blast since a declaration of emergency by President Gen. Pervez Musharraf.

The attack, possibly a suicide bomb, at the house of Amir Muqam, Minister for Political Affairs in Peshawar, northwestern Pakistan killed four people Friday, police told CNN. The minister escaped unharmed.

Earlier Friday Washington had called for restrictions on Bhutto to be lifted. Gordon Johndroe, spokesman for the White House's National Security Council, said: "Former Prime Minister Bhutto and other political party members must be permitted freedom of movement and all protesters released. It is crucial for Pakistan's future that moderate political forces work together to bring Pakistan back on the path to democracy."

Bhutto and her supporters had spent much of the day in a standoff against security forces, who placed barbed wire and barricades around her Islamabad home, preventing her attending a planned rally banned by the government, she told CNN. Watch Zain Verjee report on the showdown »

Riot police began beating Bhutto's Pakistan People's Party supporters when around 50 attempted to cut through the cordons of wire placed around her home.

An armored car carrying Bhutto approached the breach, where she -- speaking with a megaphone -- told several hundred police and security forces: "We are not the enemy; give us way."

Bhutto told the security forces: "Don't stop us, we are not the enemy. Even you in uniform are my brothers." However, the security forces refused to back down or let her through, and Bhutto returned to her home.

But she did manage to address her supporters, saying: "This barbed wire is against the hopes and peoples of Pakistan."

She said that she did not want Pakistan to suffer the extremism that had affected both Afghanistan and Iraq and urged Muslims and non-Muslims to work together. "We as a nation must save Pakistan from these extremists," she said, adding: "The message of Islam is peace." Watch Bhutto address the crowds »

Bhutto was trying to leave her compound to attend a rally in nearby Rawalpindi -- a city outside Islamabad where Pakistan's military is based -- against the state of emergency.

The former prime minister has been hoping fellow opposition parties will put their differences aside and participate as a challenge to Musharraf's government.

"Police cannot expect us not to overcome the physical barrier. They're watching us as (supporters of her Pakistan People's Party) break the barbed wire with their bare hands."

Earlier, CNN's Elise Labott in Islamabad reported seeing several protesters being dragging away and pushed into waiting vans. Some chanted slogans "down with Musharraf... bullets and batons will not last... Benazir for prime minister."

Both the bomb attack and the arrests are likely to inflame tensions. CNN's Mohsin Naqvi, reporting on the attack in northwestern Pakistan, said: "This is what we were expecting -- that militants or the people in the tribal areas, wherever they are, would be targeting something related to the government.

"We can't say how this is linked to the protests or whether it's a message to the government because militants have been targeting the government for the last two years."

Earlier Friday PPP spokeswoman Sherry Rehman said in a statement that the area around Bhutto's home was in a "virtual lockdown" and about 5,000 of Bhutto's supporters have been rounded up in efforts to foil the attempted mass protest against emergency rule.

Only members of the provincial assembly have been permitted to see the former prime minister, Rehman said.

"Thousands of PPP workers have gone underground. Roads are blocked," the statement said, adding more than 25 PPP parliament members have been detained in various police stations in Rawalpindi as they arrived from other provinces.

In addition Friday, the government also took CNN and British Broadcasting Corporation (BBC) off air for a second time as part of a media blackout, CNN's Mohsin Naqvi in Islamabad reported.

The re-imposition of a blackout on CNN and BBC comes just 24 hours after the ban on the two broadcasters was lifted.

There were fears on both the opposition and government sides that the planned rally could become violent.

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"The last time when there was a rally, there was a lot of bloodshed," Pakistani Foreign Minister Khurshid Kasuri told CNN's Zain Verjee.

"Maybe because of that the home department of the Interior Ministry feel that they wish to make sure that such ghastly incidents are never repeated again." Last month a suicide attack on Bhutto's homecoming motorcade in Karachi left more than 130 people dead.

In Rawalpindi police sources told CNN all highways feeding into the city from Punjab and North West Frontier Province (NWFP) had been barricaded and closed, with police and army rangers posted heavily throughout.

Reporting from the area where the rally was supposed to take place, CNN's Dan Rivers said the city was "basically deserted" and checkered with numerous checkpoints and hundreds of police and soldiers.

"A truckload of people were taken away in the back of a truck shouting 'Benazir! Benazir!' as we passed by," he said, adding those were the only arrests he saw.

Shops were closed, no vehicles were on the streets and major intersections were blocked off Rivers said, adding he witnessed "people wandering around not knowing what to do...very quiet indeed."

Meanwhile, Bhutto spokesman Wajid Hasan in London said that water and electricity had been cut off at the location for the rally. He said the doors to the venue had been welded shut to keep supporters out.

In enforcing the emergency order, Pakistani forces have arrested thousands of opposition leaders, lawyers, and human rights activists. Police told CNN they were working around the clock, enforcing the emergency order during the day and rounding up targeted activists at night.

Five opposition politicians -- including the head of the National Party -- were charged with treason Thursday in Karachi, a government official told CNN.E-mail to a friend